1. Field of the Invention
The present invention relates to image input devices wherein an image is formed by illuminating an image carrier such as a photographic film and the like and data is gathered in accordance therewith.
2. Description of the Related Art
Image input devices are largely divided into two classes. A first class includes those devices that include guiding units to guide illuminating light onto a transmitting original. A second class includes a scanning unit having a carriage as a retaining unit to retain a transmitting original to cause it to move, and a projection unit as a reading unit to image the transmitted light from the original on a line sensor, such as on a CCD type device.
With the aforementioned second class, focusing is caused so that the light from the illuminating unit is in the form of a line on the transmitting original. Accordingly, after such light has passed through the original it is imaged on a CCD and the transmitted light is read as a line of data. After the end of a line of data, a scanning unit performs a movement by a single line and changes the position of the transmitting original, and a readout operation is again performed. Scanning of a picture/image surface is performed by repeating reading of data and movement of the scanning unit in the aforementioned manner over a series of trials.
A typical prior art image input device is disclosed in Japanese Laid-Open Patent Publication No. 3-145881. The image input device disclosed in the aforementioned Japanese reference consists of a support body with a film insertion aperture formed in the surface. Also included therein, is a conveying unit to convey the film in a manner so that it freely reciprocates in the direction to the interior from the film insertion aperture. Additionally, an optical reading unit is disclosed and has at least one optical axis at a right angle to the conveying direction of the conveying unit.
With the prior art image input device disclosed in the aforementioned Japanese publication, a transmitting window is arranged in a conveying unit, and output adjustment (e.g., shading correction) of the reading unit is performed by reading light transmitted in the transmitting window.
The above-mentioned image input device, however, does not work well with a lengthy strip film original. More particularly, in the case where a film strip mount was used, when the film holder was inserted, the transparent window was often obstructed due to the film holder thereby requiring an output adjustment to the reading unit, which adjustment is typically not performed. Moreover, the transparent window that was not obstructed by a film holder arranged in the image input device causes the size of the device to become large as a result.
Additionally, in order for a transparent window to be arranged in a conveyance unit, the transparent window and the film as a transparent original become separately located. Because of this problem, there is a need to perform output adjustment (e.g., shading correction) of the reading unit. Accordingly, time is required to cause movement of the conveyance unit to a location at which the reading light is caused to pass through the transparent window.